Angle for Minimum Force. A box with weight w is pulled at constant speed along a level floor by a force F that is at an angle 6 above the h0ri2ontal. The coefficient of kinetic friction between the floor and box is μk
(a) In terms of 6, μk and w, calculate F.
(b) For w = 400 N and μk = 0.25, calculate F for 6 ranging from 00 to 900 in increments of 100 • Graph F versus 6. (
c) From the general expression in part (a), calculate the value of 6 for which the value of F, required to maintain constant speed, is a minimum. (Hint: At a point where a unction is minimum, what are the first and second derivatives of the function? Here F is a function of 6.) For the special case of w = 400 N and μk = 0.25, evaluate this optimal 6 and compare your result to the graph you constructed in part (b).